Beta-galactosidase for distinguishing between Citrobacter and Salmonella.
Detection of beta-galactosidase with the aid of o-nitrophenyl-beta-d-galactopyranoside (ONPG) was examined as a means for distinguishing between Citrobacter and Salmonella. Several factors which influence sensitivity and reliability of the test were studied. A bacteriostat, sodium azide, was included to permit prolonged incubation of weak and negative strains of enteric bacilli. By the procedure described, salmonellae gave negative ONPG tests; all of 171 strains of Citrobacter gave positive tests.
D001386:Azides / Q000494:pharmacology; D001431:Bacteriological Techniques; D001554:Benzene / Q000494:pharmacology; D002725:Chloroform / Q000494:pharmacology; D004925:Escherichia / Q000201:enzymology / Q000302:isolation & purification*; D005696:Galactosidases; D006863:Hydrogen-Ion Concentration; D007785:Lactose / Q000378:metabolism; D010636:Phenols / Q000494:pharmacology; D012475:Salmonella / Q000201:enzymology / Q000302:isolation & purification*; D013943:Thymol / Q000494:pharmacology; D014050:Toluene / Q000494:pharmacology
D001386:Azides; D010636:Phenols; D014050:Toluene; D013943:Thymol; D002725:Chloroform; D005696:Galactosidases; D007785:Lactose; D001554:Benzene